Clear page display after navigation if no rendered output arrives

content/browser/frame_host/render_widget_host_view_child_frame.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/resources/returned_resource.h"
 #include "cc/surfaces/surface_factory_client.h"
@@ skipping 87 matching lines @@
       ReadbackRequestCallback& callback,
       const SkColorType preferred_color_type) override;
   void CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) override;
   bool CanCopyToVideoFrame() const override;
   bool HasAcceleratedSurface(const gfx::Size& desired_size) override;
   void OnSwapCompositorFrame(uint32 output_surface_id,
                              scoped_ptr<cc::CompositorFrame> frame) override;
+  // Since the URL of content rendered by this class is not displayed in
+  // the URL bar, this method does not need an implementation.
+  void ClearCompositorFrame() override {}
   void GetScreenInfo(blink::WebScreenInfo* results) override;
   bool GetScreenColorProfile(std::vector<char>* color_profile) override;
   gfx::Rect GetBoundsInRootWindow() override;
   gfx::GLSurfaceHandle GetCompositingSurface() override;
 #if defined(USE_AURA)
   void ProcessAckedTouchEvent(const TouchEventWithLatencyInfo& touch,
                               InputEventAckState ack_result) override;
 #endif  // defined(USE_AURA)
   bool LockMouse() override;
   void UnlockMouse() override;
@@ skipping 77 matching lines @@
   }
 
  private:
   base::WeakPtrFactory<RenderWidgetHostViewChildFrame> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewChildFrame);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_